Plating apparatus



Jall- 4, 1955 H. s. SwANsoN 2,698,832

PLATING APPARATUS Filed March 20, 1951 3 Sheets-Sheet 2 5 HJM w/#W j j A ORNEYS Jan. 4, 1955 H. s. swANsoN 2,698,832

PLATING AEPARATUS Filed March 20, 1951 3 Sheets-Sheet 5 IN VENTOR HARO/ 0 5. wA/vJo/v ATTORNEYS finishing such area, and then re-etching as desired. this manner the time and expense of reproducing an en- 3 Claims. (Cl. 204-224) This invention relates to methods and apparatus for I.electroplating limited areas, and more particularly to methods and apparatus for plating limited areas for rcpairing defects in plated surfaces.

In the manufacture of rotogravure printing cylinders it is customary to provide a cylindrical base structure on, vwhich a polished shell or layer of copper is formed by electro-deposition.

A printing surface is etched in this copper layer or shell. The polished or etched surfaces of such cylinders frequently become damaged in handling. Heretofore the entire surface or etching has been necessarily renewed by grinding or stripping off the entire etched surface layer or shell, refinishing it, and re-etching the finished surface. This procedure is costly and time consuming.

I have found that it is possible to repair such damaged areas of plated and printing surfaces and the like by plating over the damaged areas, refinishing such areas and then re-etching them, thus saving considerable loss of production time and expense in high speed -rotogravure printing` operations by eliminating the necessity of reproducing the entire undamaged etched surfaces as well 1 4as reproducing the damaged areas.

have also found that changes in the etched surface may be made by replating the area to be changed, re-

tire cylinder heretofore necessary to make a small change t on a cylinder otherwise in usable condition is eliminated.

It is therefore the primary object of my present invention to provide a satisfactory method and apparatus for electroplating small areas of a metallic surface.

v Another object of this invention is to provide a portable electroplating device which is adapted for connection to any conventional alternating current outlet.

It is an important object of this invention to provide a novel method of electroplating small discrete areas where in the electrolyte is caused to iiow over the area to be plated in contact therewith and with a plating electrode.

Another object of this invention is the provision of an electroplating apparatus consisting of a unitary assembly having an applicator, receptacles for the electrolyte, and tubes interconnecting the receptacles with the applicator, to allow the flow of the'electrolyte from one receptacle through the applicator in contact with the surface being plated and into another receptacle.

An equally important object of this invention is to vprovide a novel electroplating apparatus having means dening an electrolyte chamber having an electrode therein and an opening through the walls thereof adapted for juxtaposition against a surface to be plated, and means Y United States Patent defining electrolyte inlet and outlet channels for permitj ting flow of electrolyte through said chamber in contact with the electrode and the surface to be plated.

A further obiect of this invention is to provide a novel arrangementof component parts of an electroplating assemblage whereby the heat given otf by the electrical cir l v cuit control elements is utilized for preheating the electrolyte to operating temperature.

Further objects of the invention will presently appear as the description thereof proceeds in connection with .-the appended claims and the annexed drawings in which:

Figure l is a partially sectioned front-elevational view of one embodiment of the invention illustrating the electroplating apparatus mounted within its case;

, Figure 2 is a partially sectional side-elevational view of the case and apparatus .of Figure l; -v

n 2,698,832 Patented J an. 4, 195515 ice Figure 3 is a side-elevational view showing the electroplating apparatus of Figure 1 in its operative position relative to the printing cylinder to be spot plated;

Figure 4 is an enlarged side-elevational view of the electroplating device of Figure 1;

Figure 5 is an end view of the electroplating device of Figure 1;

Figure 6 is a side elevation view showing a preferred form of the electroplating apparatus of this invention in its operative position relative to a printing cylinder to be spot plated;

Figure 7 is a fragmentary end view of the apparatus of Figure 6;

Figure 8 is a partially sectioned fragmentary elevation view of the apparatus of Figure 6, the section being taken along the line 8 8 of Figure 7; and

Figure 9 is a sectionalwview taken along the line 9 9 of Figure 7.

First embodiment Referring to the drawings, and to Figures 1 and 2 in particular, the electroplating apparatus of this invention as there shown is mounted in a case 8 so that it may be carried easily to the object to be repaired. Connections are provided so that the apparatus may be plugged into any alternating current outlet for use. The electroplating apparatus 10 is supported within case 8 upon brackets 12, which are secured to base 14 of case 8 by bolts 16, and by an additional support 18 fastened to the rear wall 20 of case 8 by bolts 22. A potentiometer 24 is secured to rear wall 20 of case 8 by means of a bracket 26 fastened to the wall by bolts 28. Access to the lower section of case 8 is provided by door 32 which is pivotally mounted to the case by a suitable hinge 34. The upper section 36 of case 8 has a door 38 pivotally mounted by hinge 40 providing access to a fuse 41, an ammeter 42 and a transformer and rectier housing 44 mounted therein. Suitable circuit connections to these circuit components are provided from power input and output plug hubs 46 and 48 as will be explained in detail later in reference to Figure 3. Case 8 is provided with a suitable handle 50 to facilitate carrying.

It has been found that better results are attained in electroplating when the temperature of the electrolyte is about 110 Fahrenheit. In order that the electrolyte v may be heated to this desired temperature prior to use of the electroplating apparatus, the electrical circuit elements, are located within the case near the electroplating apparatus so that the heat given olf thereby when connected to a suitable power source may be utilized to heat the electrolyte. These circuit elements are energized by connection of power input plug hub 46 to an alternating current outlet socket as a power source so that current will pass through these circuit elements.

The electroplating apparatus, as is best shown in Figures 4 and 5, includes an applicator S2 and a pair of electrolyte receptacles 54 and 56 suitably interconnected by channels to permit ow by gravity of the electrolyte from the upper to the lower receptacle through the applicator 52 and to permit flow of displaced air from the lower to the upper receptacle.

The two receptacles 54 and S6 ofthe electroplating apparatus are preferably made of glass and are spaced from each other on the legs of a triangular shaped frame 58. Receptacles 54 and 56 are secured to frame 58 by encircling bands which are fastened to frame 58 by nuts and bolts 62. Each receptacle is provided at its open end with a stopper 64 and 66 of rubber or other suitable material, each of which has three longitudinally extending holes formed therethrough.

Short tubes 68 and 70 formed cf glass or other suitable material, extend through the center holes of Stoppers 64 and 66 respectively their inner ends being ush with the inner surface of the Stoppers while the outer ends extend slightly above the outer surface thereof. Long tubes 72 and 74, which extend through one of the outer holes of each stopper, are bent slightly within the receptacles adjacent the inner surfaces of the Stoppers and extend 84 and 86 extend through the remaining holes in'stoppers 64 and 66. The outer ends of the tubes all extend substantially the same distance above the exterior surfaces of Stoppers 64 and 66. h

The applicator 52 is secured to the frame 58 by identical plates 88 one on each side and each having curved portions 90. ends to the legs of frame 58 by bolts 92, the electrolyte applicator 52 being supported between the curved portions 90. The electrolyte applicator body 94 is made o f rubber or any other suitable insulating material and is formed with a hole through which a copper anode 96 extends. A protruding portion 98 of the body 94 is formed with a concave surface 100, and is surrounded by a cup shaped yapplicator head 102 to define an electrolyte chamber 104 therebetween into which one end ofthe copper anode 96 projects. A pair of passages 106 and 108 through which electrolyte passes to and from the chamber 104 are formed through the body 94. Short pieces of tubing 110 and 112 are inserted on the outer ends of passages 106 and 108 respectively so that portions thereof project from the opposite ends of the body 94. Suitable electrolyte conducts 114 and 116 are provided to interconnect the passages 106 and 108 with the center tubes 68 and 70 of the receptacles. Ari annular flexible ring 118 is secured around an opening 119 through the wall of the applicator head 102 to provide a liquid tight seal between the article being plated and the applicator head during plating operation. Suitable conduits 120 and 122 are provided for transferring the air from one receptacle to the other, conduit 120 interconnecting tubes 74 and 76 and conduit 122 interconnecting tubes 72 and 78. A suitable handle 123 is provided for holding the apparatus while in use.

`As previously pointed out, prior to use of this electroplating apparatus, alternating current power input plug hub 46 is connected to a suitable power source to energize the transformer and rectifier within housing 44 and the potentiometer 24. Suicient heat will be generated within case 8 by these elements to raise the temperature of the bottles of electrolyte secured therein to the desired degree. When the electrolyte is heated to the desired temperature, the electroplating apparatus is removed from the case. A two wirev direct current power output cable 124 is connected to the rectifier and controls through output plug hub 48, as shown in Figure 3. The positive terminal 126 of cable 124 is connected to copper anode 96 while the negative terminal 128 is connected to the body to be plated such as the printing cylinder 130. The electroplating apparatus is then held against the printing cylinder in such a position so that the exible ring 118 surrounds the damaged surface or spot upon the cylinder to provide a liquid tight connection between the electrolyte chamber 104 and the surface to be plated.

The electrolyte in the upper receptacle 54 flows through tube 68, conduit 114, and passage 106, into chamber 104 Where it is in contact With the defective area of the printing cylinder, through passage 108, conduit 116, and tube 70,.into the receptacle 56. As the lower receptacle received the electrolyte the displaced air therein flows through the flattened open end 86 of tube 78, through tube channel 122, and tube 72 into the upper end of the receptacle above the level of the electrolyte therein, designated by line 131. The flattened end portion 84 of tube 76 pointing downward when submerged in the electrolyte and the restricted size of the opening prevent any substantial flow of electrolyte through channel 120 with the apparatus in the position shown.

When all of the electrolyte has flowed from the upper to the lower receptacle, the electroplating operation may be continued if necessary by rotating the apparatus 8 through 180 about the axis of the anode 96 to reverse the flow of electrolyte between the receptacles. The reversing of the apparatus 10 and the ow of the electrolyte keep the electrolyte continuously agitated to produce a more satisfactory plating solution.

The electrical connections of the apparatus are shown diagrainmatically in Figure 3. The power input leads 132 and 134 from the plug 46 are connected across the primary winding 136 of transformer 138. The secondary winding 140 of transformer 138 is connected to a substantially conventional full-wave rectifier system, the output of which is connected across potentiometer 24,

Plates 88 are secured at their oppositey the center tap 142 of secondary winding 140 being connected to one end terminal 143 of potentiometer 24 and the end terminals of secondary winding being connected through rectifiers 144 and 146 to a common line 148 connected to the opposite end terminal 149 of potentiometer 24. Fuses 150 and 152 are placed in series between rectifiers 144 and 146 and the respective ends of the secondary winding 140 with which they are associated. A pilot light 154 is connected across secondary winding 140, to indicate that the apparatus is connected to a power source, being conveniently connected between the end terminals of fuses 150 and 152 as shown. As thus connected a pulsating uni-directional voltage will be developed across potentiometer 24. The variable center tap 156 of potentiometer 24 is connected through one of the wires 124 to the negative terminal or cathode 128 while the end terminal 143 or potentiometer 24 is connected through ammeter 42 and fuse 41 in series to the positive terminal 126 which is connected to the copper anode 96. The electroplating current through the electrolyte and therefore the rate of electro-deposition of metal may thus be controlled by adjusting the position of tap 156.

It should be noted that pulsating uni-direction current passes through potentiometer 24 and rectifiers 144 and 146 and that alternating current is impressed upon the transformer 138 so long as the power input plug of 46 is connected to a power source. The heat given off by these elements is that utilized for preheating the electrolyte.

Second embodiment The second and preferred embodiment of this invention is disclosed in Figures 6 to 9. This embodiment differs from the first embodiment primarily in the structural details of the applicator head and in the arrangement of the liquid seal between the surface to the plated and the applicator head during the plating operation.

Referring to Figure 6, it will be noted that the preferred form of electroplating apparatus includes a pair of electrolyte receptacles 200 and 202 suitably secured to the angularly related arms 204 and 206 of a support bracket, that an applicator head 208 is suitably mounted at the intersection of the arms 204 and 206 upon which the receptacles are mounted, and that suitable conduits l are provided interconnecting the receptacles with the applicator head for permitting flow of electrolyte therethrough and interconnecting the two receptacles to permit flow of air therebetween, all as in the previous embodiment.

Referring to Figures 7, 8, and 9, it will be noted that the applicator head 208 consists primarily of a body member 210 and a cap 212. The body member 210, which is preferably formed of Lucite or other suitable insulating material, is formed with a square portion 214, a cylindrical portion 216, and a substantially rectangular portion 218 formed diametrally across the planar face 219 of the cylindrical portion 216. Cap 212 is generally cylindrical in shape, being provided with a chamfered edge as indicated at 220, and is provided with al coaxially aligned cylindrical recess 222 and a diametral slot 224 milled through the end wall 225 of cap 212. Cap 212 is also formed of Lucite or other'suitable electrical insulating material.

Cap 212 ts onto the body member 210, the cylindrical portion 216 of member 210 fitting snugly within the cylindrical recess 222 or" cap 212 and the end surface of the rectangular portion 218 being in surface engagement with the end walls 226 of the recess 222. When thus fitted together two chambers 228 and 230 which have the shape of segments of cylinders, are formed and are separated by the substantially rectangular portion 218 of body member 210.

As is best shown in Figure 9, the milled slot 224 in the cap 212 defines a passage between the two chambers 228 and 230. A fluid passage interconnecting chamber 230 and flexible tubing 232 is defined by intersecting bores 234 and 236 formed through the body member 210, bore 234 opening into the chamber 230 and bore 236 having a sleeve 238 inserted therein to which flexible tubing 232 is secured. In a like manner a passage interconnecting flexible tubing 240 with the chamber 228 is defined by intersecting bores 242 and 244, bore244 also being provided with a sleeve (not shown) to which the flexible tubing 240 is secured. As may be seen by reference to Figure 6, iiexible tubings 232 and 240 connect the applicator head with the receptacles 202 and 200 respectively.

Referring once again to Figure 9, a cylindrical copper anode 246 extends through an aperture 248 formed axially through the body member 210. A copper block 250, which is generally rectangular in shape, is secured to the end of rod 246 and ts snugly within the slot 224 formed through the cap 212. For rotation of block 250 relative to body 210, anode connection screw 254 is loosened.

With the electroplating apparatus in the position shown in Figure 6 so that the flow of electrolyte is from receptacle 200 to receptacle 202, the direction of ilow will be through flexible tubing 240 into bore 244 and, as viewed in Figure 9, through bore 242, chamber 228, the milled slot 224 around the block 250, chamber 230, intersecting bores 234 and 236, and flexible tubing 232 to the receptacle 202. Upon reversal of the position of the receptacles, the direction of flow of the electrolyte will, of course, be reversed.

It should be noted that cap 212 is rotatable relative to body member 210. By this construction, the slot 224 can be readily aligned with the area to be plated and the remainder of the assembly rotated through 180'relative thereto for reversal electrolyte flow as often as may be necessary for a given plating job.

In order to perform an electroplating operation with this preferred form of the apparatus, a flexible rubber mat 256 formed with a central aperture 258 is placed on the surface to be plated in such a position that the aperture 258 surrounds the area to be plated. If but a limited area smaller than the size of aperture 258 is to be plated, masking tape may be applied to the metal surface around the area to be plated before the mat 256 is put in place. Mat 256 may be secured to the surface to be plated by any suitable means such as a form of adhesive tape (not shown). The size of aperture 258 is such that the outer end of cap 212 will t snugly therein so that the chamfered portion 220 will form a liquid tight seal with the rubber mat 256 and so that the edges of the slot 224 will surround the area to be plated.

The mode of operation, the mounting case, and the electrical circuit for this embodiment of the invention are substantially the same as that for the first embodiment, the negative terminal 22S being electrically connected to the cylinder to be plate and the positive terminal 126 being electrically connected to the copper anode 246.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A portable apparatus for electroplating small discrete areas of a surface comprising a support having a handle thereon, a pair of receptacles mounted on said support in spaced relation adapted to be alternately held in a vertical relation one above the other by said support, a hollow body structure mounted on said support defining an electrolyte chamber, a wall on said body Structure adapted to be pressed in sealed Contact with a surface over an area to be plated and having an opening therein connecting said chamber and area to be plated, an anode mounted in said chamber, passage means in said body structure operatively connected to said chamber, and conduit means operatively connecting said receptacles and passage means whereby an electrolyte is permitted to flow from the upper receptacle to said chamber to contact said anode and area to be plated and thence to said lower receptacle where said electrolyte is received prior to reversing the position of said receptacle for continued plating.

2. Apparatus for electroplating small discrete areas of a surface comprising body member having a pair of independent fluid passages formed therethrough and terminating in a common end face of said body member, a partition projecting from said body member end face between the ends of said fluid passages, a cap having an elongated aperture formed through the end wall thereof and rotatably mounted on said body structure, said cap and said partition have abutting planar faces disposed normal to the axis of rotation of said cap relative to said body, the length of said elongated aperture at said planar face of said cap being greater than the width of said partition at the said planar face thereof, an electrode rotatably mounted upon said end face of said partition and located within said elongated aperture of said cap, the length of said electrode within said aperture being less than the length of said aperture whereby a stream of electrolyte flowing between said passages passes over said partition and the electrode mounted thereon into the confines of the cap end wall elongated aperture, a support structure adapted to be manually held providing a mount for said body member, and means including an electrolyte reservoir mounted on said support structure defining a closed fluid circuit for circulating eleccsltrolyte through said fluid passages over said electro e.

3. The electroplating apparatus det-ined in claim 2 together with means forming a uid tight seal between said cap and a surface about the area thereof to be plated.

References Cited in the le of this patent UNITED STATES PATENTS 732,616 Burgess et al June 30, 1903 1,285,875 Woodbury Nov. 26, 1918 1,426,769 Pinney Aug. 22, 1922 1,771,680 Ishisaka July 29, 1930 2,046,440 Adey Iuly 7, 1936 2,108,700 Adey Feb. l5, 1938 2,115,403 Verschragen Apr. 26, 1938 2,146,924 Adey Feb. 14, 1939 FOREIGN PATENTS 26,504 Great Britain of 1912 

1. A PORTABLE APPARATUS FOR ELECTROPLATING SMALL DISCRETE AREAS OF A SURFACE COMPRISING A SUPPORT HAVING A HANDLE THEREON. A PAIR OF RECEPTACLES MOUNTED ON SAID SUPPORT IN SPACED RELATION ADAPTED TO BE ALTERNATELY HELD IN A VERTICAL RELATION ONE ABOVE THE OTHER BY SAID SUPPORT, A HOLLOW BODY STRUCTURE MOUNTED ON SAID SUPPORT DEFINING AN ELECTROLYTE CHAMBER, A WALL ON SAID BODY STRUCTURE ADAPTED TO BE PRESSED IN SEALED CONTACT WITH A SURFACE OVER AN AREA TO BE PLATED AND HAVING AN OPENING THEREIN CONNECTING SAID CHAMBER AND AREA TO BE PLATED, AN ANODE MOUNTED IN SAID CHAMBER, PASSAGE MEANS IN SAID BODY STRUCTURE OPERATIVELY CONNECTED TO SAID CHAMBER, AND CONDUIT MEANS OPERATIVELY CONNECTING SAID RECEPTACLES AND PASSAGE MEANS WHEREBY AN ELECTROLYTE IS PERMITTED TO FLOW FROM THE UPPER RECEPTACLE TO SAID CHAMBER TO CONTACT SAID ANODE AND AREA TO BE PLATED AND THENCE TO SAID LOWER RECEPTACLE WHERE SAID ELECTROLYTE IS RECEIVED PRIOR TO REVERSING THE POSITION OF SAID RECEPTACLE FOR CONTINUED PLATING. 